My engine light flashes and then turns off, but only when using 3rd gear on the J Shifter. I do not have the issue when in drive or the rarely used 4th gear. It just started after I had some maintenance done to the vehicle at a local, independent shop.

The maintenance done was a main crank pully (old one almost fully seperated but did throw my belt). I had the rear diff fluid replaced at the same shop and my front fog lamp lens replaced (took a rock this winter).

Thoughts?

 

PM Brutal (Jag Tech) if he doesn't respond to this thread.

 

I would be concerned that they mat have damaged the flexplate reluctor that the crank trigger reads for cylinder firing and misfire monitoring. If damaged it can make the ECU think the engine is misfiring.
The flashed CEL is misfires or something else wrong severe enough to cause damage. Thats why it flashes. I useally only see this for misfires. Is it running differantly when this happens??
This is just outloud thinking based on unfo. I would like to see what codes you have. You may need to have it monitored while you duplicate it driving